Observations on the Foraging Behavior and Avian Prey of the Neotropical Carnivorous Bat, Vampyrum spectrum

The foraging behavior of Vampyrum spectrum was studied in the field by radio-tracking, evening roost observations, and systematic collection of the prey parts found in the bottom of a roost containing five bats. Field observations, roost monitoring, and netting records all suggest that the bats hunt solitarily. One radiotracked bat hunted over an area of 3.2 hectares, and spent most of its time in deciduous woodland, secondary growth, and forest edge, rather than in the riparian forest where the roost was located. The avian prey species were identified from the feathers collected in the roost over a one-year period. Of the 18 species (about 86 individuals) identified, most were common residents of the tropical dry deciduous forest. Non-passerines were significantly preferred over passerines. Vampyrum appear to select birds which weigh between 20 and 150 grams (g), sleep in foliage rather than in holes or burrows, and either roost communally or have a strong body odor. It appears that the bats locate their avian prey by scent rather than by vision or echolocation.